UV/ozone Treatment of the Pyrethroid Insecticide Fenvalerate in Aqueous Solutions

Fenvalerate is a common Pyrethroid insecticide exits stably in water and soil. This study subjected to enhance the degradation of fenvalerate (in the form of aqueous emulsion of a commercial formulation) using UV/ozone process. Experiment results indicated that fenvalerate was decomposed rapidly under UV irradiation (99% within 10 minutes). Degradation yield also showed an increase when ozone was applied. UV/ozone degradation rates of fenvalerate followed first-order kinetics. In alkaline medium, there was a slight increase in yield. Sodium nitrate acted as a photo-sensitizer for UV irradiation process so it helped to increase reaction rate at an optimum concentration of 2.5 mM. Moreover, some degradation products were identified and tentatively assigned by GC-MS.